import os
if 'KUROKO_TEST_ENV' in os.environ:
    return 0

from time import sleep
from fileio import open, stdin
from threading import Thread

let d = []
let stop = False

for y in range(0x40):
    let l = []
    for x in range(0x40):
        l.append(0)
    d.append(l)

class NoisePainter(Thread):
    def run(self):
        let myRando = open('/dev/urandom','rb')
        while not stop:
            let bytes = myRando.read(3)
            let x = bytes[0] & 0x3F
            let y = bytes[1] & 0x3F
            d[y][x] = bytes[2]

let painters = [NoisePainter() for i in range(5)]

for painter in painters:
    painter.start()

def drawScreen():
    print("\[[H",end="")
    for y in range(0x20):
        for x in range(0x40):
            let top = d[y*2][x]
            let bottom = d[y*2+1][x]
            print("\[[38","2",top,top,top,"48","2",bottom,bottom,bottom,sep=";",end="m▀")
        print("\[[0m")

for i in range(5):
    drawScreen()

stop = True
for painter in painters:
    painter.join()

drawScreen()
return 0